This invention relates generally to operations involving the handling and deployment of sand control screens used in down hole oil and gas well completion packing operations and more particularly to the apparatus used to make up and uncouple the various screen assemblies used in such operations.
After the open hole in a well has been cleaned, what is known in the art as a gravel-packing screen and/or gravel-packing tool assemblies are run into the well bore. The tool assembly is usually run with one or more subsection screen sections extending from the toe of the well to the well casing with at least one joint located inside the well casing followed by several joints of blank tubing before being connected to a shear-out safety joint and the gravel pack tool itself. A wash pipe is usually run inside the screen for effective circulation of fluids.
The function of the gravel pack tool is to maintain hydrostatic pressure on the open-hole section of the well at all times to prevent bore hole collapse. Maintaining a hydrostatic over-balance throughout all operations and the use of proper fluid characteristics eliminates the need to run alternative flow path devices.
When running the gravel pack tool and the various screen assemblies in or out of the well bore, a screen table or support structure adaptively fixed to the rotary table located at the drill rig floor, is used to catch or capture the sand screen subsections of the tool assembly at each joint connection. The tubing string containing the screens is thus suspended within the well bore without damaging the screens or the gravel packer itself. The screen table is used to support the string in place of pipe slips because of the limited space at the joint between the screen subsections and to prevent damage to the screens. However, in some cases, slips are used in conjunction with the screen table to capture and suspend the wash pipe being inserted or withdrawn from within the screen string assembly.
Presently the screen and wash pipe connections are made up with conventional pipe wrenches or manual pipe tongs. However, recent requirements make it necessary to apply specified torques to these joints, thereby presenting a problem. Conventional power tongs having torque setting capability are simply too large due to space limitations and too expensive to downsize in most cases due to limited applications requirements.
Until recently hand tongs or pipe wrenches had no torque setting capability. Generally only the larger tongs and pipe spinner system have torque control and presetting capability. However, in some cases, torque indication systems have been employed whereby the tong or other such gripping tools are attached to a cable (cat line) that in turn is attached to a load cell. This arrangement requires significant time to set up and use and requires significantly more space than is generally available when working with sand screen replacement. Such systems are inherently inaccurate, dangerous, cumbersome, and lack efficiency.
A more unitized hand tong is available that utilizes a traditional torque setting handle integral with the tong as seen in U.S. Pat. No. 6,439,064. However, even this tool is too slow in some cases and requires a significant amount of labor, generally two men to manipulate the tong and a backup gripping tool in place and then apply the proper torque to each joint.
A more convenient and labor reducing assembly is obviously needed that allows for both a relatively small torque head and backup tong assembly. The tong assembly should remain in place adjacent the centerline of the well bore and be capable of swiftly coupling and uncoupling sand screens where space between the screen elements is minimal. It is equally important that the tong assembly be capable of coupling and uncoupling wash pipe being inserted within the sand screen string, also with preset torque capability. It would be advantageous for such an arrangement to utilize a manual tong assembly with shorter tong handles than are in current use and be confined to within the perimeter of the screen or rotary table and further reduce the manpower required to make up such connections. It is therefore an object of the following disclosure to provide such an apparatus.
A screen table and tong assembly whereby a sand screen table structure adaptable to a rotary table is used to capture and suspend sand screen subsections within the well bore is further adapted to include a pair of articulated opposing manual tong assemblies. The tong assemblies are pivotal and transversely positionable relative to the screen table. Provision is made for adapting a slip set in cooperation with said screen table and tong assembly for capturing and supporting wash pipe within the sand screen subsections. Additional adaptations include a custom spinner tong assembly for rotating the sand screen tubular subsections and wash pipe sections.
The tongs and their torque arm assemblies are interchangeable with a range of tong heads of different types and sizes including pipe wrenches, chain tongs, and strap wrenches and provide reversibility between left and right hand torque applications.